Data received for this study are based on pyrometallurgical operations only.

This activity includes: 1) Copper ore mining; 2) Copper ore concentrate preparation and delivery; 3) Production of matte copper; 4) Production of blister copper; 5) Production of copper anodes and 6) Production of primary copper. Production and use of electricity and fuel used in the processes are included.

Below is a description of the included operations.

-- 1) Ore mining --The copper ore mining method used is determined by the size, shape and depth below the surface of the ore body. Most copper ores are mined by open pit mining in which large quarries are opened, the ore broken away from the deposits by use of explosives and shovelled into trucks.Actual energy requirements vary widely depending on the characteristics of the mine and ore handling techniques used. The type and the amount of ore deposit and the overlying rock and dirt and the depth of the seam below the surface, affect the level of energy needed for mining the ore.The data for copper mining have been received from three mining companies. The data cover the mining of 45 million tonnes of ore.

-- 2) Ore concentrate preparation and delivery --It is normal practice for mining companies to prepare or concentrate before shipping to reduce the amount of material to be transported. The data mainly relates to transportation of ore concentrate by rail and sea. Transporting the concentrate by sea is exstensive. It is assumed that average shipping and rail transport distances were 10 000 km and 500 km respectively. The data cover preparation of 2 million tonnes of concentrate

-- 3) Production of matte copper --Here the ore concentrate, mixed with flux and other additives, is charged in a fuelfired smelting furnace where it is melted. The molten mass is allowed to separate into two layers. The upper slag layer, made up of iron silicate with less than 0,5% of copper, is normally discarded. The lower matte layer, with about 40% to 75% of copper, and containing most of original metal present, is transferred to the converting step to produce blister copper.

-- 4) Production of blister copper --During the production of blister copper the matte is converted to blister in a converter by oxidation in two stages. In the first stage iron sulphide is oxidised and fluxed to form slag which may contain copper (1-5%). The converter slag is ususally recycled back to the smelting furnace. With all the iron removed, the remaining copper sulphide is further oxidised to blister copper.

--5) Production of copper anodes --The blister copper from the converter is transferred to anode furnace to reduce the residual sulphur as well as the oxygen levels in the metal. The data cover the production of 1 million tonnes of copper anodes.

-- 6) Production of primary copper --The metal at the anode stage still has some impurities (such as As, Bi, Ni, Pb and Sb) left along with precious metals (such as Ag, Au, Pt and Pd). These are separated from the copper by electro- refining into primary copper. The data covers the production of 900 000 tonnes of primary copper.

Some of the data on air and water emissions was provided in a form which made it impractical to calculate emissions for unit mass of product output. For example, from an air emission value given in the units of mg/m3 of air, it is not possible to calculate the total emission unless the total volume of air is known and this is seldom measured in pactice.Therefor, where available, only emission values associated with the given amount of product made are used.

Time Boundary

The data comes from mining companies and producers of primary copper for the operations during the 12 month period in 1995 (information why the year 1995 was chosen is not available).

Geographical
Boundary

The data comes mainly from European operations.Futher information of the geographical boundaries is not available.

Other Boundaries

The copper producing industry is international.

Allocations

The first thing that has been done to analyse this system is to break down the complex system into a series of separate sub-systems each of which produces a single product but which, when added together, exhibit the same charateristics as the original single system. In this study has co-product allocation and Stoichiometric allocation been applied. It is not often that practical processes exactly match for example the stoichiometric rules and an alternative method using mass must be applied.

The purpose of this work was to produce life-cycle inventory data for the production of primary copper based on data submitted by members of the International Copper Association from their own operations.

Detailed Purpose

The aim is to provide ’’cradle to gate’’ data for the production of primary copper.

Commissioner

The International Copper Association .

Practitioner

Boustead, Ian Dr.

Reviewer

Applicability

There is no recommendation of how to use the data from this report.

This activity is a ’’cradle to gate’’ system for primary copper production. In the sequence of operations leading up to primary copper production there are six main stages involved. These are 1) Copper ore mining; 2) Copper ore concentrate preparation and delivery; 3) Production of matte copper; 4) Production of blister copper; 5) Production of copper anodes and 6) Production of primary copper.

All six stages in the primary copper production have been described cumulatively in separate activities in the database.

About Data

The data used for electricity and fuel production in the calculations leading to the results reported comes from the reports of International Energy Agency.

Data Assumptions:Data received from participating companies show sometime wide variation with respect to metal contents of ore and various intermediate products such as concentrates, gas dust and scrap.Therefor has the following assumptions been made:

1. Copper content in ore. Where actual data on copper content of the ore were available these were used. Otherwise the content was calculated on the basis of mass flow.

2. Copper content of matte according to published literature is between 40% to 75%. The assumption made, where the copper content in matte was not derived from mass flow, is therefor 60 %.

3.Average copper content of blister was assumed to be 98,5%, based on published litterature.

4. Average copper content of copper anode was assumed to be 99.5% based om published literature.

5.Where the amount of SO2 gas is shown as one of the output products, it is regarded as 100 % pure.

6. There is also some loss of copper during ore preperation and the smelting and recovery processes. The loss can be calculated from the mass flow if accurate contents of the input and output materials where known.Where this is not possible, the loss is assumed to be 1% at each step of the sequence of operations. It is further assumed that there is another 4% loss of copper during the operational steps from ore preperation to electro-refining, making the total loss of copper to 5%.

Notes

The results in the report of the Ecoprofile study has been broken down into a number of categories, identifying the type of operation that gives rise to them. The categories are:1. Fuel production2. Fuel use3. Process4. Transport5. Biomass (inputs and outputs associated with the use of biological materials such as wood)